Geobge blythe



(No Model.)

G.BL'YTHE.

SPIRIT LEVEL.

No. 339,369. Patented Apr. 6, 1886.

WITNESSES INVENT R J. 06 MM 7 Attorney Pnmo-uma nphur. Wuhmgtcll, D. c

UNITED STATES PATENT tribe.

GEORGE BLYTHE, OF GHILLICOTHE, MISSOURI.

SPiRlT-LEVEL.

SPECIFICATION forming part Of Letters Patent No. 339,369, dated April 6, 1886.

Application filed August 11, 1885.

To all whom it may concern:

Be it known that I, GEORGE BLYTHE, a citizen of the United States, residing at Chillicothe, in the county of Livingston and State of Missouri, have invented certain new and useful Improvements in Sight-Slots for Levels, of which the following is a. full, clear, and exact description.

In the use of what is commonly called a spirit-level for ascertaininghorizontal lines great in con venience has often been experienced from inability to readily inspect the bubble as it moves back and forth in the glass tube or vial. This is due. to the fact that the edges of the sight-slot in the metal plate covering the vial-socket is of such height as to cast a shadow across the slot and upon the vial or tube.

Now, the object of myinvention isto remedy this defect; and to that end I make the slot wider for a short distance at or near its middle than for the remainder of its length.

In the accompanying drawings, in which similar letters of reference indicate corresponding parts, Figure 1 illustrates in perspective view a level provided with my improvement. Fig. 2 is a top plan view of the plate removed.

The letter-a designates the level-stock,wliicl1 is of the usual material and construction.

b represents the ordinary glass vial con taining the usual liquid and bubble.

0 represents the usual metal plate used to cover the socket containing the vial or glass tube to protect the latter.

(2 represents the slot, which I propose to widen at or near its middle, and in this par- Serial No. 174,123. (No model.)

ticular instance I have done so by cutting in one side thereof two elongated notches or in dentations, d, leaving a portion of the edge or a centralprojectingportion,e,which,whileallowing the bubble to be readily seen, serves as a guard to prevent the vial being accidentally broken at the widened portion of the slot of the metal plate, and also serves as a center indicator, as will be readily understood. Across this projection, and at right angles to the vial or tube, is made the usual line for indicating, in connection with the bubble, the horizontal position of the instrument.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A flat metallic plate for covering the bubble vial or tube of a levelinginstrunient, having a longitudinal slot, (1, and provided in the edge at one side of said slot with the lateral notches or recesses d d, forming a projection, e, between the recesses, substantially as set forth.

. 2. The combination,inaleveling-instrument,

with the stock and tube, of a flat metallic plate arranged horizontally above the tube, and having a slot extending longitudinally with relation to the tube, and provided at one side of said slot with lateral notches or recesses d d, forming a projection, 6, between said notches, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE BLYJHE.

Vitnesses:

R0131. S. MooRn, W. H. BoorH. 

